feat: Graceful shutdown with old web server (#2786)

- Stop accepting connections during graceful shutdown in the old web server
- Stop all the services before Clio exits
- Move cache saving into stop callback

src/util/StopHelper.cpp

@@ -19,6 +19,8 @@
 
 #include "util/StopHelper.hpp"
 
+#include "util/Spawn.hpp"
+
 #include <boost/asio/spawn.hpp>
 #include <boost/asio/steady_timer.hpp>
 
@@ -37,7 +39,7 @@ void
 StopHelper::asyncWaitForStop(boost::asio::yield_context yield)
 {
     boost::asio::steady_timer timer{yield.get_executor(), std::chrono::steady_clock::duration::max()};
-    onStopReady_.connect([&timer]() { timer.cancel(); });
+    onStopReady_.connect([&]() { util::spawn(yield, [&timer](auto&&) { timer.cancel(); }); });
     boost::system::error_code error;
     if (!*stopped_)
         timer.async_wait(yield[error]);

src/util/StopHelper.hpp

@@ -36,6 +36,16 @@ class StopHelper {
     std::unique_ptr<std::atomic_bool> stopped_ = std::make_unique<std::atomic_bool>(false);
 
 public:
+    StopHelper() = default;
+    ~StopHelper() = default;
+
+    StopHelper(StopHelper&&) = delete;
+    StopHelper&
+    operator=(StopHelper&&) = delete;
+    StopHelper(StopHelper const&) = delete;
+    StopHelper&
+    operator=(StopHelper const&) = delete;
+
     /**
      * @brief Notify that the class is ready to stop.
      */